This allows for e.g. Jedi to infer types (it checks the name).
It was only used to support Python 3.5.0/3.5.1, where this is is not
available in the `typing` module.
Ref: https://github.com/davidhalter/jedi/issues/1472
Uses `TYPE_CHECKING = False` in `_pytest.outcomes` to avoid having to
work around circular import.
This should increase coverage for subprocesses, where previously
`source` paths were used only from the config file, but not the initial
`--source` argument.
- Skips pypy for coverage, reports only py37 to coveralls
- tox: allow for TOXENV=py37-coverage
- tracks coverage in subprocesses, using coverage-enable-subprocess, and
parallel=1
- removes usedevelop with doctesting to match `--source` being used with
coverage
- keep coveralls for now, used with AppVeyor